Online Tone Generator
Instrument MIDI
TiMidity++
Open source MIDI to WAVE converter / player
JJazzLab
JJazzLab is the free backing track application. It automatically generates backing tracks for any song. It’s a jam buddy to have fun improvising, learn new stuff or just practice your instrument.
Anvil Studio | Free music composition, notation & MIDI-creation software
Free Windows multi-track MIDI/Audio recording & editing, VST Effects & Instruments, automation. Options for Sheet Music printing, music theory, ear training.
rakarrack
rakarrack effects processor homepage
Patroneo - Laborejo Software
LSS is a group of programs to make music.
Dubler 2 | Vochlea
Convert your voice into a live MIDI controller with Dubler 2. Hum synths, beatbox drums, and manipulate effects and filters with your voice.
Kmetronome · SourceForge
MIDI Software by Pedro Lopez-Cabanillas
Drumstick MIDI monitor
Drumstick MIDI Monitor for Linux
PianoBooster